New Scientist ( Wednesday, January 17, 2007 ) —
A Cheap and Simple Cure for Cancer?
by
Andy Coghlan
New Scientist has received an unprecedented amount of interest in this story from readers. If you would like up-to-date information on any plans for clinical trials of DCA in patients with cancer, or would like to donate towards a fund for such trials, please visit the site set up by the University of Alberta and the Alberta Cancer Board (http://www.depmed.ualberta.ca/dca ). We will also follow events closely and will report any progress as it happens.
It is rare to find a drug that sweeps away decades of assumptions and reveals a radical approach to treating all forms of a disease. But a simple, small molecule called dichloroacetate (DCA) has done just that – and to that most dreaded of diseases: cancer.
The new findings (http://www.newscientist.com/article/dn10971-cheap-safe-drug-kills-most-cancers.html ) might also force a rethink on what actually causes cells to turn cancerous in the first place.
In 1930, biochemist Otto Warburg, proposed that cells turn cancerous through a fundamental change in the way they generate their energy. Normally, cells use specialised organelles called mitochondria to supply their energy. Cancer cells shift to a process called glycolysis which takes place in the main body of the cell. Glycolysis is an inefficient system of making energy which normal cells employ only when oxygen is in short supply, switching to mitochondrial energy production when oxygen levels increase.
Curiously, Warburg discovered that cancer cells continue to use glycolysis even when oxygen is plentiful. He called this the Warburg effect, and claimed it was common to all cancer cells.
His ideas were dismissed and buried long ago, not least when another famous biochemist, Hans Krebs, said the Warburg effect was a symptom of cancer, not the primary cause. This scepticism was reinforced by the belief that cancer cells switch to glycolysis because their mitochondria are damaged and dont work any more.
Enter DCA, which has been used for years to treat people with mitochondrial disease. The drug boosts the ability of mitochondria to generate energy. When given to cancer cells it did the same: the cells switched from glycolysis to mitochondrial energy production. What’s more, functional mitochondria help cells recognise functional abnormalities and trigger cell death.
In tests, the DCA caused cancer cells to lose their immortality and die. When the drug was given to rats with human tumours, the tumours shrank. Warburg may have been right after all – glycolysis may be more than just a symptom of cancer.
So why not rush straight into clinical trials with this drug? It is cheap, does not appear to affect normal cells, we know its side effects, and it should work on all cancers.
There’s a hitch: dichloroacetate is an old drug and so cannot be patented. The upshot is that pharmaceutical companies cant stop rivals making and selling it more cheaply, so its not worth their while to go to the huge expense of testing it in clinical trials.
This is not a new problem. Many drugs are left on the shelf because companies cannot make lots of money from them. It has happened for diseases that affect mainly poor people, such as TB, although there are now an increasing number of initiatives to help deal with these cases. But cancer is historically a disease that chiefly afflicts the rich, and testing DCA will need a one-off effort.
Drugs companies will be falling over themselves to find a patentable drug with similar action to DCA. Any of these that reach the market will be hugely expensive. It would be a scandal if a cheap alternative with such astonishing potential were not given a chance simply because it won’t turn a big enough profit.
The Official University of Alber
www.depmed.ualberta.ca
